Climate change is expected to have a big impact on crop yields and food security over the coming decades, as farmers contend with rising temperatures and increasingly abnormal conditions. Scientists working on solutions to this problem continue to demonstrate how gene-editing tools like CRISPR could have a role to play, and a group in Japan has now leveraged the technology to produce a mutant species of barley that avoids premature sprouting.
As one of the world's most widely grown crops, barley is used in everything from breads, cereals, animal fodder and of course as a source of malt for alcoholic beverages including beer and whisky. One problem that barley farmers often run into, however, is known as pre-harvest sprouting, where high humidity due to unexpected rain in the lead up to harvest causes premature germination, significantly devaluing the grain.
Prior research has shown how genetic engineering can be used to extend the dormancy of the grains to prevent this from happening, but this can negatively impact their use in malt production down the track. Scientists have been working to solve this dilemma for years, and through the CRISPR gene editing tool, a team at Okoyama University believe they have landed on a solution.
“We recognized the need to strategically manipulate crops to weather the effects of steadily exacerbating climate change," says Dr Hiroshi Hisano, who led the study. "Since our collaborative research group had already developed expertise in precision genome editing of barley, we decided to go with the same initially. Also, previous studies have pinpointed specific grain and seed dormancy genes in barley, called qsd1, and qsd2. Hence, our modus operandi was pretty clear.”
The scientists used a species of barley known as Golden Promise as their starting point, and used CRISPR to create genetically engineered versions with mutants of either one or both of these dormancy genes. All of these mutants exhibited a buildup of what's known as abscisic acid, a characteristic in line with delayed germination, but the team's analysis revealed there were a number of other factors at play. Germination could be promoted by treating the mutants with hydrogen peroxide, for example, as it could by exposure to cold temperatures. Qsd1 mutants exhibited partially reduced grain dormancy, while the qsd2 mutants could germinate in the dark, but not in the light.
“We could successfully produce mutant barley that was resistant to pre-harvest sprouting, using the CRISPR/Cas9 technology," says Hisano. "Also, our study has not only clarified the roles of qsd1 and qsd2 in grain germination or dormancy, but has also established that qsd2 plays a more significant role.”
The research marks an important step forward in efforts to fine-tune the world's most widely-used crops to better handle the effects of climate change, a field of research where we have seen some promising advances of late. This includes editing potato and rice RNA to boost yields by 50 percent, engineering crops to require 25 percent less water, creating broccoli for all seasons and even altering crops so they store more carbon underground.
The study was published in the Plant Biotechnology Journal.
Source: Okayama University via EurekAlert
